This invention relates to a foundation construction wherein recycled tire walls are used to form a substrate layer for aggregate and concrete foundations.
When constructing foundations for roadways and other similar load bearing surfaces, it is common practice to layer the ground with aggregate material such as gravel. The aggregate material forms a stable base for the foundation. Under certain conditions however, the aggregate material is known to penetrate into the soil and lose stability over time. The use of a substrate layer between the aggregate material and the ground is known for distributing the loads supported on the foundation and for reducing the penetration of the aggregate material into the ground.
U.S. Pat. No. 5,846,021 to Bailey et al describes a road base construction wherein a plurality of recycled tire portions are coupled together to form a matrix for supporting aggregate thereon. The tire portions include a side wall and an adjacent portion of the tread of the tire such that when the tire portions are laid out on the ground the tread portion extends generally upward for coupling to adjacent tires. The loads are distributed between the tire portions through the couplings mounting them together. The ability of the matrix to distribute loads is thus dependent upon the strength of the couplings rather than the durability of the tires themselves.
According to one aspect of the present invention there is provided a foundation comprising:
a layer of aggregate material supported on the ground; and
a substrate layer located adjacent the ground supporting the aggregate material thereon such that the aggregate material is prevented from penetrating into the ground;
the substrate layer comprising a plurality of generally flat annular members comprising recycled side wall portions of automotive tires, the annular members being located in an overlapping arrangement such that each annular member overlaps at least one adjacent annular member, the annular members forming a substantially planar surface.
The use of side wall portions from recycled tires allows the members to be overlapped such that the loads are distributed across ground by the substrate layer without depending on couplings for securing the tires together and for distributing the loads therebetween.
The side wall portions are preferably located in the overlapping arrangement such that a circular opening defined within each annular member is substantially free from obstruction by the overlapping adjacent annular members for permitting drainage therethrough.
Each recycled portion may comprise a bead of the corresponding side wall or alternatively, a bead and an adjacent portion of the corresponding side wall.
A plurality of fasteners may be provided for coupling the annular members together adjacent an overlapping portion of each annular member.
According to a further aspect of the present invention there is provided a method of constructing a foundation using recycled automotive tires, said method comprising;
providing a plurality of automotive tires;
forming a plurality of generally flat annular members from respective side walls of the tires;
positioning the annular members in overlapping configuration such that the annular members form continuous substrate layer;
covering the annular members with aggregate material.
The method may include pouring concrete over the aggregate material.
Forming each annular member may comprise cutting a bead from a corresponding side wall of a tire. Alternatively, forming each annular member may comprise cutting a bead and an adjacent portion of the side wall from one of the tires.
The method may include fastening each annular member to at least one adjacent member before covering the members with aggregate material.
The annular members are preferably positioned such that a circular opening defined within each member is substantially free from obstruction from adjacent annular members to permit drainage through the substrate layer.